diff --git a/README.md b/README.md
index 739c8cf..e800d97 100644
--- a/README.md
+++ b/README.md
@@ -87,3 +87,10 @@ Future versions of Attainly may include:
 Attainly is built around a simple idea:
 
 Large goals become attainable when they are broken into clear, scheduled steps and completed consistently over time.
+
+## Development Login
+
+The seeded local development account uses these credentials:
+
+- Email: `user@example.com`
+- Password: `password`
diff --git a/backend/app/Auth/BcryptPasswordHasher.php b/backend/app/Auth/BcryptPasswordHasher.php
new file mode 100644
index 0000000..0bc4a46
--- /dev/null
+++ b/backend/app/Auth/BcryptPasswordHasher.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace App\Auth;
+
+class BcryptPasswordHasher implements PasswordHasher
+{
+    public function hash(string $password): string
+    {
+        return password_hash($password, PASSWORD_DEFAULT);
+    }
+
+    public function verify(string $password, string $hash): bool
+    {
+        return password_verify($password, $hash);
+    }
+}
diff --git a/backend/app/Auth/PasswordHasher.php b/backend/app/Auth/PasswordHasher.php
new file mode 100644
index 0000000..ab57a41
--- /dev/null
+++ b/backend/app/Auth/PasswordHasher.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace App\Auth;
+
+interface PasswordHasher
+{
+    public function hash(string $password): string;
+
+    public function verify(string $password, string $hash): bool;
+}
diff --git a/backend/app/Auth/RandomTokenGenerator.php b/backend/app/Auth/RandomTokenGenerator.php
new file mode 100644
index 0000000..0615bff
--- /dev/null
+++ b/backend/app/Auth/RandomTokenGenerator.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Auth;
+
+class RandomTokenGenerator implements TokenGenerator
+{
+    public function generate(): string
+    {
+        return bin2hex(random_bytes(32));
+    }
+}
diff --git a/backend/app/Auth/TokenGenerator.php b/backend/app/Auth/TokenGenerator.php
new file mode 100644
index 0000000..39b4263
--- /dev/null
+++ b/backend/app/Auth/TokenGenerator.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace App\Auth;
+
+interface TokenGenerator
+{
+    public function generate(): string;
+}
diff --git a/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUser.php b/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUser.php
new file mode 100644
index 0000000..7e8c92c
--- /dev/null
+++ b/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUser.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace App\Auth\UseCases\AuthenticateUser;
+
+use App\Auth\PasswordHasher;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\UnauthorizedException;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\User;
+use App\User\UserRepository;
+
+class AuthenticateUser
+{
+    public function __construct(
+        private UserRepository $userRepo,
+        private PasswordHasher $hasher,
+    ) {}
+
+    /**
+     * @throws BadRequestException
+     * @throws UnauthorizedException
+     */
+    public function execute(AuthenticateUserRequest $request): User
+    {
+        if ($request->email === null || $request->email === '') {
+            throw new BadRequestException('email is required');
+        }
+        if ($request->password === null || $request->password === '') {
+            throw new BadRequestException('password is required');
+        }
+
+        $user = $this->userRepo->findByEmail(
+            new EmailAddress($request->email)
+        );
+        if ($user === null) {
+            throw new UnauthorizedException('invalid credentials');
+        }
+
+        $passwordMatches = $this->hasher->verify(
+            $request->password,
+            $user->getPasswordHash(),
+        );
+        if (! $passwordMatches) {
+            throw new UnauthorizedException('invalid credentials');
+        }
+
+        return $user;
+    }
+}
diff --git a/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUserRequest.php b/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUserRequest.php
new file mode 100644
index 0000000..aa8b1df
--- /dev/null
+++ b/backend/app/Auth/UseCases/AuthenticateUser/AuthenticateUserRequest.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Auth\UseCases\AuthenticateUser;
+
+class AuthenticateUserRequest
+{
+    public function __construct(
+        public ?string $email,
+        public ?string $password,
+    ) {}
+}
diff --git a/backend/app/Auth/UseCases/CreateSession/CreateSession.php b/backend/app/Auth/UseCases/CreateSession/CreateSession.php
new file mode 100644
index 0000000..db6403f
--- /dev/null
+++ b/backend/app/Auth/UseCases/CreateSession/CreateSession.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Auth\UseCases\CreateSession;
+
+use App\Auth\Clock;
+use App\Auth\CreateSessionDto;
+use App\Auth\Session;
+use App\Auth\SessionRepository;
+use App\Auth\TokenGenerator;
+use App\User\User;
+
+class CreateSession
+{
+    private const SESSION_LIFETIME = '+7 days';
+
+    public function __construct(
+        private SessionRepository $sessionRepo,
+        private TokenGenerator $tokenGenerator,
+        private Clock $clock,
+    ) {}
+
+    public function execute(User $user): Session
+    {
+        $now = $this->clock->now();
+        $expiresAt = $now->modify(self::SESSION_LIFETIME);
+
+        return $this->sessionRepo->create(new CreateSessionDto(
+            token: $this->tokenGenerator->generate(),
+            user: $user,
+            createdAt: $now,
+            expiresAt: $expiresAt,
+        ));
+    }
+}
diff --git a/backend/app/Exceptions/BadRequestException.php b/backend/app/Exceptions/BadRequestException.php
new file mode 100644
index 0000000..b900f47
--- /dev/null
+++ b/backend/app/Exceptions/BadRequestException.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace App\Exceptions;
+
+use DomainException;
+
+class BadRequestException extends DomainException {}
diff --git a/backend/app/Exceptions/UnauthorizedException.php b/backend/app/Exceptions/UnauthorizedException.php
new file mode 100644
index 0000000..f5d406e
--- /dev/null
+++ b/backend/app/Exceptions/UnauthorizedException.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace App\Exceptions;
+
+use DomainException;
+
+class UnauthorizedException extends DomainException {}
diff --git a/backend/app/Http/Controllers/AuthController.php b/backend/app/Http/Controllers/AuthController.php
index de82e1a..a9c1960 100644
--- a/backend/app/Http/Controllers/AuthController.php
+++ b/backend/app/Http/Controllers/AuthController.php
@@ -2,22 +2,83 @@
 
 namespace App\Http\Controllers;
 
+use App\Auth\UseCases\AuthenticateUser\AuthenticateUser;
+use App\Auth\UseCases\AuthenticateUser\AuthenticateUserRequest;
+use App\Auth\UseCases\CreateSession\CreateSession;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\UnauthorizedException;
+use App\Http\Middleware\AuthMiddleware;
+use App\Shared\Http\RequestInput;
 use App\User\User;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Cookie;
 
 class AuthController extends Controller
 {
+    public function __construct(
+        private AuthenticateUser $authenticateUser,
+        private CreateSession $createSession,
+    ) {}
+
+    public function login(Request $request): JsonResponse
+    {
+        $input = new RequestInput($request);
+
+        try {
+            $user = $this->authenticateUser->execute(
+                new AuthenticateUserRequest(
+                    email: $input->string('email'),
+                    password: $input->string('password'),
+                )
+            );
+        } catch (BadRequestException $exception) {
+            return new JsonResponse(
+                ['error' => $exception->getMessage()], 400
+            );
+        } catch (UnauthorizedException $exception) {
+            return new JsonResponse(
+                ['error' => $exception->getMessage()], 401
+            );
+        }
+
+        $session = $this->createSession->execute($user);
+
+        $response = new JsonResponse([
+            'user' => $this->userPayload($user),
+        ], 200);
+
+        return $response->withCookie(Cookie::create(
+            name: AuthMiddleware::COOKIE_NAME,
+            value: $session->getToken(),
+            expire: $session->getExpiresAt()->getTimestamp(),
+            path: '/',
+            domain: null,
+            secure: false,
+            httpOnly: true,
+            raw: false,
+            sameSite: Cookie::SAMESITE_LAX,
+        ));
+    }
+
     public function me(Request $request): JsonResponse
     {
         /** @var User $user */
         $user = $request->attributes->get('user');
 
         return new JsonResponse([
-            'user' => [
-                'id' => $user->getId(),
-                'email' => $user->getEmail()->value(),
-            ],
+            'user' => $this->userPayload($user),
         ]);
     }
+
+    /**
+     * @return array{id: int, email: string}
+     */
+    private function userPayload(User $user): array
+    {
+        return [
+            'id' => $user->getId(),
+            'email' => $user->getEmail()->value(),
+        ];
+    }
 }
diff --git a/backend/app/Providers/AppServiceProvider.php b/backend/app/Providers/AppServiceProvider.php
index 52192d0..36ac77d 100644
--- a/backend/app/Providers/AppServiceProvider.php
+++ b/backend/app/Providers/AppServiceProvider.php
@@ -2,10 +2,14 @@
 
 namespace App\Providers;
 
+use App\Auth\BcryptPasswordHasher;
 use App\Auth\Clock;
 use App\Auth\EloquentSessionRepository;
+use App\Auth\PasswordHasher;
+use App\Auth\RandomTokenGenerator;
 use App\Auth\SessionRepository;
 use App\Auth\SystemClock;
+use App\Auth\TokenGenerator;
 use App\User\EloquentUserRepository;
 use App\User\UserRepository;
 use Carbon\CarbonImmutable;
@@ -29,6 +33,8 @@ class AppServiceProvider extends ServiceProvider
             SessionRepository::class,
             EloquentSessionRepository::class,
         );
+        $this->app->bind(PasswordHasher::class, BcryptPasswordHasher::class);
+        $this->app->bind(TokenGenerator::class, RandomTokenGenerator::class);
         $this->app->bind(Clock::class, SystemClock::class);
     }
 
diff --git a/backend/app/Shared/Http/RequestInput.php b/backend/app/Shared/Http/RequestInput.php
new file mode 100644
index 0000000..6dffb92
--- /dev/null
+++ b/backend/app/Shared/Http/RequestInput.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Shared\Http;
+
+use Illuminate\Http\Request;
+
+class RequestInput
+{
+    public function __construct(private Request $request) {}
+
+    public function string(string $key): ?string
+    {
+        $value = $this->request->input($key);
+        if (is_string($value)) {
+            return $value;
+        }
+        if (is_int($value) || is_float($value) || is_bool($value)) {
+            return (string) $value;
+        }
+
+        return null;
+    }
+}
diff --git a/backend/app/User/CreateUserDto.php b/backend/app/User/CreateUserDto.php
index 735320b..e0267b6 100644
--- a/backend/app/User/CreateUserDto.php
+++ b/backend/app/User/CreateUserDto.php
@@ -8,5 +8,6 @@ final readonly class CreateUserDto
 {
     public function __construct(
         public EmailAddress $email,
+        public string $passwordHash,
     ) {}
 }
diff --git a/backend/app/User/EloquentUserRepository.php b/backend/app/User/EloquentUserRepository.php
index 5996528..cee7817 100644
--- a/backend/app/User/EloquentUserRepository.php
+++ b/backend/app/User/EloquentUserRepository.php
@@ -10,6 +10,7 @@ class EloquentUserRepository implements UserRepository
     {
         $model = UserModel::create([
             'email' => $dto->email->value(),
+            'passwordHash' => $dto->passwordHash,
         ]);
 
         return $this->toDomain($model);
@@ -25,11 +26,24 @@ class EloquentUserRepository implements UserRepository
         return $this->toDomain($model);
     }
 
+    public function findByEmail(EmailAddress $email): ?User
+    {
+        $model = UserModel::query()
+            ->where('email', $email->value())
+            ->first();
+        if ($model === null) {
+            return null;
+        }
+
+        return $this->toDomain($model);
+    }
+
     private function toDomain(UserModel $model): User
     {
         return new User(
             id: $model->id,
             email: new EmailAddress($model->email),
+            passwordHash: $model->passwordHash,
         );
     }
 }
diff --git a/backend/app/User/User.php b/backend/app/User/User.php
index 8c9fa9c..3501bee 100644
--- a/backend/app/User/User.php
+++ b/backend/app/User/User.php
@@ -9,6 +9,7 @@ final readonly class User
     public function __construct(
         private int $id,
         private EmailAddress $email,
+        private string $passwordHash,
     ) {}
 
     public function getId(): int
@@ -20,4 +21,9 @@ final readonly class User
     {
         return $this->email;
     }
+
+    public function getPasswordHash(): string
+    {
+        return $this->passwordHash;
+    }
 }
diff --git a/backend/app/User/UserModel.php b/backend/app/User/UserModel.php
index 74f3211..d2c64e3 100644
--- a/backend/app/User/UserModel.php
+++ b/backend/app/User/UserModel.php
@@ -9,6 +9,7 @@ use Illuminate\Database\Eloquent\Model;
 /**
  * @property int $id
  * @property string $email
+ * @property string $passwordHash
  *
  * @method static Builder<static>|UserModel newModelQuery()
  * @method static Builder<static>|UserModel newQuery()
@@ -16,7 +17,7 @@ use Illuminate\Database\Eloquent\Model;
  *
  * @mixin \Eloquent
  */
-#[Fillable(['email'])]
+#[Fillable(['email', 'passwordHash'])]
 class UserModel extends Model
 {
     protected $table = 'users';
diff --git a/backend/app/User/UserRepository.php b/backend/app/User/UserRepository.php
index 5fcd6eb..4805f3f 100644
--- a/backend/app/User/UserRepository.php
+++ b/backend/app/User/UserRepository.php
@@ -2,9 +2,13 @@
 
 namespace App\User;
 
+use App\Shared\ValueObject\EmailAddress;
+
 interface UserRepository
 {
     public function create(CreateUserDto $dto): User;
 
     public function find(int $id): ?User;
+
+    public function findByEmail(EmailAddress $email): ?User;
 }
diff --git a/backend/database/migrations/0001_01_01_000000_create_users_table.php b/backend/database/migrations/0001_01_01_000000_create_users_table.php
index dafb6c2..065daab 100644
--- a/backend/database/migrations/0001_01_01_000000_create_users_table.php
+++ b/backend/database/migrations/0001_01_01_000000_create_users_table.php
@@ -11,6 +11,7 @@ return new class extends Migration
         Schema::create('users', function (Blueprint $table): void {
             $table->id();
             $table->string('email')->unique();
+            $table->string('passwordHash');
         });
     }
 
diff --git a/backend/database/seeders/UserSeeder.php b/backend/database/seeders/UserSeeder.php
index 886e4c9..ef163e1 100644
--- a/backend/database/seeders/UserSeeder.php
+++ b/backend/database/seeders/UserSeeder.php
@@ -2,15 +2,29 @@
 
 namespace Database\Seeders;
 
-use App\User\UserModel;
+use App\Auth\PasswordHasher;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use App\User\UserRepository;
 use Illuminate\Database\Seeder;
 
 class UserSeeder extends Seeder
 {
+    public const string EMAIL = 'user@example.com';
+
+    public const string PASSWORD = 'password';
+
     public function run(): void
     {
-        UserModel::firstOrCreate([
-            'email' => 'user@example.com',
-        ]);
+        $userRepository = app(UserRepository::class);
+        $email = new EmailAddress(self::EMAIL);
+        if ($userRepository->findByEmail($email) !== null) {
+            return;
+        }
+
+        $userRepository->create(new CreateUserDto(
+            email: $email,
+            passwordHash: app(PasswordHasher::class)->hash(self::PASSWORD),
+        ));
     }
 }
diff --git a/backend/routes/api.php b/backend/routes/api.php
index d8fba04..d2e63d8 100644
--- a/backend/routes/api.php
+++ b/backend/routes/api.php
@@ -4,6 +4,8 @@ use App\Http\Controllers\AuthController;
 use App\Http\Middleware\AuthMiddleware;
 use Illuminate\Support\Facades\Route;
 
+Route::post('/login', [AuthController::class, 'login']);
+
 Route::middleware(AuthMiddleware::class)->group(function (): void {
     Route::get('/me', [AuthController::class, 'me']);
 });
diff --git a/backend/tests/Fakes/FakePasswordHasher.php b/backend/tests/Fakes/FakePasswordHasher.php
new file mode 100644
index 0000000..9e93325
--- /dev/null
+++ b/backend/tests/Fakes/FakePasswordHasher.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Tests\Fakes;
+
+use App\Auth\PasswordHasher;
+
+class FakePasswordHasher implements PasswordHasher
+{
+    public function hash(string $password): string
+    {
+        return 'hashed:'.$password;
+    }
+
+    public function verify(string $password, string $hash): bool
+    {
+        return $this->hash($password) === $hash;
+    }
+}
diff --git a/backend/tests/Fakes/FakeTokenGenerator.php b/backend/tests/Fakes/FakeTokenGenerator.php
new file mode 100644
index 0000000..54926f3
--- /dev/null
+++ b/backend/tests/Fakes/FakeTokenGenerator.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Tests\Fakes;
+
+use App\Auth\TokenGenerator;
+use RuntimeException;
+
+class FakeTokenGenerator implements TokenGenerator
+{
+    private int $callCount = 0;
+
+    /**
+     * @param  string[]  $tokens
+     */
+    public function __construct(private array $tokens) {}
+
+    public function generate(): string
+    {
+        if ($this->callCount >= count($this->tokens)) {
+            throw new RuntimeException('FakeTokenGenerator exhausted');
+        }
+
+        $token = $this->tokens[$this->callCount];
+        $this->callCount++;
+
+        return $token;
+    }
+}
diff --git a/backend/tests/Fakes/FakeUserRepository.php b/backend/tests/Fakes/FakeUserRepository.php
new file mode 100644
index 0000000..3672f87
--- /dev/null
+++ b/backend/tests/Fakes/FakeUserRepository.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Tests\Fakes;
+
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use App\User\User;
+use App\User\UserRepository;
+
+class FakeUserRepository implements UserRepository
+{
+    /**
+     * @var array<int, User>
+     */
+    private array $users = [];
+
+    public function create(CreateUserDto $dto): User
+    {
+        $id = count($this->users) + 1;
+        $user = new User(
+            id: $id,
+            email: $dto->email,
+            passwordHash: $dto->passwordHash,
+        );
+        $this->users[$id] = $user;
+
+        return $this->copy($user);
+    }
+
+    public function find(int $id): ?User
+    {
+        $user = $this->users[$id] ?? null;
+
+        return $user === null ? null : $this->copy($user);
+    }
+
+    public function findByEmail(EmailAddress $email): ?User
+    {
+        foreach ($this->users as $user) {
+            if ($user->getEmail()->value() === $email->value()) {
+                return $this->copy($user);
+            }
+        }
+
+        return null;
+    }
+
+    private function copy(User $user): User
+    {
+        return new User(
+            id: $user->getId(),
+            email: $user->getEmail(),
+            passwordHash: $user->getPasswordHash(),
+        );
+    }
+}
diff --git a/backend/tests/Feature/Auth/AuthMiddlewareTest.php b/backend/tests/Feature/Auth/AuthMiddlewareTest.php
index 8d84a1d..91d7be3 100644
--- a/backend/tests/Feature/Auth/AuthMiddlewareTest.php
+++ b/backend/tests/Feature/Auth/AuthMiddlewareTest.php
@@ -101,6 +101,7 @@ class AuthMiddlewareTest extends TestCase
     ): User {
         $user = app(UserRepository::class)->create(new CreateUserDto(
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         ));
         app(SessionRepository::class)->create(new CreateSessionDto(
             token: $token,
diff --git a/backend/tests/Feature/Auth/EloquentSessionRepositoryTest.php b/backend/tests/Feature/Auth/EloquentSessionRepositoryTest.php
index 32d170d..25f9fe5 100644
--- a/backend/tests/Feature/Auth/EloquentSessionRepositoryTest.php
+++ b/backend/tests/Feature/Auth/EloquentSessionRepositoryTest.php
@@ -20,6 +20,7 @@ class EloquentSessionRepositoryTest extends TestCase
     {
         $user = app(UserRepository::class)->create(new CreateUserDto(
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         ));
         $createdAt = $this->utc('2026-07-31T12:00:00');
         $expiresAt = $this->utc('2026-08-07T12:00:00');
@@ -61,6 +62,7 @@ class EloquentSessionRepositoryTest extends TestCase
     {
         $user = app(UserRepository::class)->create(new CreateUserDto(
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         ));
         $repository = app(SessionRepository::class);
         $repository->create(new CreateSessionDto(
diff --git a/backend/tests/Feature/Auth/LoginEndpointTest.php b/backend/tests/Feature/Auth/LoginEndpointTest.php
new file mode 100644
index 0000000..bab28b8
--- /dev/null
+++ b/backend/tests/Feature/Auth/LoginEndpointTest.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Tests\Feature\Auth;
+
+use App\Auth\PasswordHasher;
+use App\Auth\SessionRepository;
+use App\Http\Middleware\AuthMiddleware;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use App\User\UserRepository;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class LoginEndpointTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_login_returns_user_and_sets_session_cookie(): void
+    {
+        $email = 'user@example.com';
+        $password = 'correct-password';
+        $passwordHash = app(PasswordHasher::class)->hash($password);
+        app(UserRepository::class)->create(new CreateUserDto(
+            email: new EmailAddress($email),
+            passwordHash: $passwordHash,
+        ));
+
+        $response = $this->postJson('/api/login', [
+            'email' => $email,
+            'password' => $password,
+        ]);
+
+        $response->assertOk();
+        $response->assertJsonPath('user.email', $email);
+
+        $cookie = $response->getCookie(
+            AuthMiddleware::COOKIE_NAME,
+            false,
+        );
+        $this->assertNotNull($cookie);
+        $this->assertNotNull(
+            app(SessionRepository::class)->findByToken(
+                $cookie->getValue(),
+            ),
+        );
+    }
+}
diff --git a/backend/tests/Feature/Auth/MeEndpointTest.php b/backend/tests/Feature/Auth/MeEndpointTest.php
index ec19fc3..3cabaf1 100644
--- a/backend/tests/Feature/Auth/MeEndpointTest.php
+++ b/backend/tests/Feature/Auth/MeEndpointTest.php
@@ -25,6 +25,7 @@ class MeEndpointTest extends TestCase
         );
         $user = app(UserRepository::class)->create(new CreateUserDto(
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         ));
         app(SessionRepository::class)->create(new CreateSessionDto(
             token: 'valid-token',
diff --git a/backend/tests/Feature/Database/DatabaseSeederTest.php b/backend/tests/Feature/Database/DatabaseSeederTest.php
index 26b6b06..ca1ec91 100644
--- a/backend/tests/Feature/Database/DatabaseSeederTest.php
+++ b/backend/tests/Feature/Database/DatabaseSeederTest.php
@@ -2,6 +2,9 @@
 
 namespace Tests\Feature\Database;
 
+use App\Auth\PasswordHasher;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\UserRepository;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Tests\TestCase;
 
@@ -17,6 +20,20 @@ class DatabaseSeederTest extends TestCase
         $this->assertDatabaseHas('users', [
             'email' => 'user@example.com',
         ]);
+        $this->assertDatabaseMissing('users', [
+            'email' => 'user@example.com',
+            'passwordHash' => 'password',
+        ]);
         $this->assertDatabaseCount('users', 1);
+
+        $user = app(UserRepository::class)->findByEmail(
+            new EmailAddress('user@example.com'),
+        );
+
+        $this->assertNotNull($user);
+        $this->assertTrue(app(PasswordHasher::class)->verify(
+            'password',
+            $user->getPasswordHash(),
+        ));
     }
 }
diff --git a/backend/tests/Feature/User/EloquentUserRepositoryTest.php b/backend/tests/Feature/User/EloquentUserRepositoryTest.php
index 207523f..5741cb5 100644
--- a/backend/tests/Feature/User/EloquentUserRepositoryTest.php
+++ b/backend/tests/Feature/User/EloquentUserRepositoryTest.php
@@ -17,6 +17,7 @@ class EloquentUserRepositoryTest extends TestCase
         $repository = app(UserRepository::class);
         $user = $repository->create(new CreateUserDto(
             email: new EmailAddress('Founder@EXAMPLE.COM'),
+            passwordHash: 'hashed-password',
         ));
 
         $this->assertGreaterThan(0, $user->getId());
@@ -28,6 +29,10 @@ class EloquentUserRepositoryTest extends TestCase
             'id' => $user->getId(),
             'email' => 'Founder@example.com',
         ]);
+        $this->assertDatabaseHas('users', [
+            'id' => $user->getId(),
+            'passwordHash' => 'hashed-password',
+        ]);
 
         $foundUser = $repository->find($user->getId());
 
@@ -37,6 +42,10 @@ class EloquentUserRepositoryTest extends TestCase
             $user->getEmail()->value(),
             $foundUser->getEmail()->value(),
         );
+        $this->assertSame(
+            $user->getPasswordHash(),
+            $foundUser->getPasswordHash(),
+        );
     }
 
     public function test_it_returns_null_for_an_unknown_user(): void
@@ -45,4 +54,28 @@ class EloquentUserRepositoryTest extends TestCase
 
         $this->assertNull($repository->find(999));
     }
+
+    public function test_it_finds_a_user_by_email(): void
+    {
+        $repository = app(UserRepository::class);
+        $createdUser = $repository->create(new CreateUserDto(
+            email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
+        ));
+
+        $foundUser = $repository->findByEmail(
+            new EmailAddress('user@EXAMPLE.COM'),
+        );
+
+        $this->assertNotNull($foundUser);
+        $this->assertSame($createdUser->getId(), $foundUser->getId());
+    }
+
+    public function test_it_returns_null_for_an_unknown_email(): void
+    {
+        $repository = app(UserRepository::class);
+        $this->assertNull($repository->findByEmail(
+            new EmailAddress('unknown@example.com'),
+        ));
+    }
 }
diff --git a/backend/tests/Unit/Auth/Middleware/AuthMiddlewareTest.php b/backend/tests/Unit/Auth/Middleware/AuthMiddlewareTest.php
index 65908c7..d6a72a1 100644
--- a/backend/tests/Unit/Auth/Middleware/AuthMiddlewareTest.php
+++ b/backend/tests/Unit/Auth/Middleware/AuthMiddlewareTest.php
@@ -154,6 +154,7 @@ class AuthMiddlewareTest extends TestCase
         return new User(
             id: 7,
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         );
     }
 }
diff --git a/backend/tests/Unit/Auth/SessionTest.php b/backend/tests/Unit/Auth/SessionTest.php
index 7804333..264033c 100644
--- a/backend/tests/Unit/Auth/SessionTest.php
+++ b/backend/tests/Unit/Auth/SessionTest.php
@@ -16,6 +16,7 @@ class SessionTest extends TestCase
         $user = new User(
             id: 7,
             email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed-password',
         );
         $createdAt = $this->utc('2026-07-31T12:00:00');
         $expiresAt = $this->utc('2026-08-07T12:00:00');
@@ -40,6 +41,7 @@ class SessionTest extends TestCase
             user: new User(
                 id: 7,
                 email: new EmailAddress('user@example.com'),
+                passwordHash: 'hashed-password',
             ),
             createdAt: $this->utc('2026-07-31T12:00:00'),
             expiresAt: $expiresAt,
diff --git a/backend/tests/Unit/Auth/UseCases/AuthenticateUserTest.php b/backend/tests/Unit/Auth/UseCases/AuthenticateUserTest.php
new file mode 100644
index 0000000..585af22
--- /dev/null
+++ b/backend/tests/Unit/Auth/UseCases/AuthenticateUserTest.php
@@ -0,0 +1,104 @@
+<?php
+
+namespace Tests\Unit\Auth\UseCases;
+
+use App\Auth\UseCases\AuthenticateUser\AuthenticateUser;
+use App\Auth\UseCases\AuthenticateUser\AuthenticateUserRequest;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\UnauthorizedException;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use App\User\User;
+use PHPUnit\Framework\TestCase;
+use Tests\Fakes\FakePasswordHasher;
+use Tests\Fakes\FakeUserRepository;
+
+class AuthenticateUserTest extends TestCase
+{
+    private FakeUserRepository $userRepository;
+
+    private FakePasswordHasher $passwordHasher;
+
+    private AuthenticateUser $useCase;
+
+    protected function setUp(): void
+    {
+        $this->userRepository = new FakeUserRepository;
+        $this->passwordHasher = new FakePasswordHasher;
+        $this->useCase = new AuthenticateUser(
+            $this->userRepository,
+            $this->passwordHasher,
+        );
+    }
+
+    public function test_null_email_throws_bad_request(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('email is required');
+
+        $this->useCase->execute(new AuthenticateUserRequest(
+            email: null,
+            password: 'correct-password',
+        ));
+    }
+
+    public function test_null_password_throws_bad_request(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('password is required');
+
+        $this->useCase->execute(new AuthenticateUserRequest(
+            email: 'user@example.com',
+            password: null,
+        ));
+    }
+
+    public function test_unknown_email_throws_unauthorized(): void
+    {
+        $this->expectException(UnauthorizedException::class);
+        $this->expectExceptionMessage('invalid credentials');
+
+        $this->useCase->execute(new AuthenticateUserRequest(
+            email: 'unknown@example.com',
+            password: 'correct-password',
+        ));
+    }
+
+    public function test_wrong_password_throws_unauthorized(): void
+    {
+        $this->createUser('correct-password');
+        $this->expectException(UnauthorizedException::class);
+        $this->expectExceptionMessage('invalid credentials');
+
+        $this->useCase->execute(new AuthenticateUserRequest(
+            email: 'user@example.com',
+            password: 'wrong-password',
+        ));
+    }
+
+    public function test_valid_credentials_return_user(): void
+    {
+        $user = $this->createUser('correct-password');
+
+        $authenticatedUser = $this->useCase->execute(
+            new AuthenticateUserRequest(
+                email: 'user@example.com',
+                password: 'correct-password',
+            ),
+        );
+
+        $this->assertSame($user->getId(), $authenticatedUser->getId());
+        $this->assertSame(
+            $user->getEmail()->value(),
+            $authenticatedUser->getEmail()->value(),
+        );
+    }
+
+    private function createUser(string $password): User
+    {
+        return $this->userRepository->create(new CreateUserDto(
+            email: new EmailAddress('user@example.com'),
+            passwordHash: $this->passwordHasher->hash($password),
+        ));
+    }
+}
diff --git a/backend/tests/Unit/Auth/UseCases/CreateSessionTest.php b/backend/tests/Unit/Auth/UseCases/CreateSessionTest.php
new file mode 100644
index 0000000..4d85166
--- /dev/null
+++ b/backend/tests/Unit/Auth/UseCases/CreateSessionTest.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace Tests\Unit\Auth\UseCases;
+
+use App\Auth\UseCases\CreateSession\CreateSession;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\User;
+use DateTimeImmutable;
+use DateTimeZone;
+use PHPUnit\Framework\TestCase;
+use Tests\Fakes\FakeClock;
+use Tests\Fakes\FakeSessionRepository;
+use Tests\Fakes\FakeTokenGenerator;
+
+class CreateSessionTest extends TestCase
+{
+    private DateTimeImmutable $now;
+
+    private FakeSessionRepository $sessionRepository;
+
+    private CreateSession $useCase;
+
+    protected function setUp(): void
+    {
+        $this->now = new DateTimeImmutable(
+            '2026-07-31T12:00:00',
+            new DateTimeZone('UTC'),
+        );
+        $this->sessionRepository = new FakeSessionRepository;
+        $this->useCase = new CreateSession(
+            $this->sessionRepository,
+            new FakeTokenGenerator(['session-token']),
+            new FakeClock($this->now),
+        );
+    }
+
+    public function test_creates_a_seven_day_session_with_generated_token(): void
+    {
+        $user = $this->user();
+
+        $session = $this->useCase->execute($user);
+
+        $this->assertSame('session-token', $session->getToken());
+        $this->assertSame($user, $session->getUser());
+        $this->assertSame($this->now, $session->getCreatedAt());
+        $this->assertEquals(
+            $this->now->modify('+7 days'),
+            $session->getExpiresAt(),
+        );
+    }
+
+    public function test_created_session_is_findable_by_token(): void
+    {
+        $this->useCase->execute($this->user());
+
+        $session = $this->sessionRepository->findByToken('session-token');
+
+        $this->assertNotNull($session);
+        $this->assertSame(7, $session->getUser()->getId());
+    }
+
+    private function user(): User
+    {
+        return new User(
+            id: 7,
+            email: new EmailAddress('user@example.com'),
+            passwordHash: 'hashed:correct-password',
+        );
+    }
+}
diff --git a/backend/tests/Unit/Http/Controllers/AuthControllerTest.php b/backend/tests/Unit/Http/Controllers/AuthControllerTest.php
new file mode 100644
index 0000000..cded75c
--- /dev/null
+++ b/backend/tests/Unit/Http/Controllers/AuthControllerTest.php
@@ -0,0 +1,127 @@
+<?php
+
+namespace Tests\Unit\Http\Controllers;
+
+use App\Auth\UseCases\AuthenticateUser\AuthenticateUser;
+use App\Auth\UseCases\CreateSession\CreateSession;
+use App\Http\Controllers\AuthController;
+use App\Http\Middleware\AuthMiddleware;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use DateTimeImmutable;
+use DateTimeZone;
+use Illuminate\Http\Request;
+use PHPUnit\Framework\TestCase;
+use Tests\Fakes\FakeClock;
+use Tests\Fakes\FakePasswordHasher;
+use Tests\Fakes\FakeSessionRepository;
+use Tests\Fakes\FakeTokenGenerator;
+use Tests\Fakes\FakeUserRepository;
+
+class AuthControllerTest extends TestCase
+{
+    private FakeUserRepository $userRepository;
+
+    private FakePasswordHasher $passwordHasher;
+
+    private FakeSessionRepository $sessionRepository;
+
+    private AuthController $controller;
+
+    protected function setUp(): void
+    {
+        $this->userRepository = new FakeUserRepository;
+        $this->passwordHasher = new FakePasswordHasher;
+        $this->sessionRepository = new FakeSessionRepository;
+        $authenticateUser = new AuthenticateUser(
+            $this->userRepository,
+            $this->passwordHasher,
+        );
+        $createSession = new CreateSession(
+            $this->sessionRepository,
+            new FakeTokenGenerator(['session-token']),
+            new FakeClock(new DateTimeImmutable(
+                '2026-07-31T12:00:00',
+                new DateTimeZone('UTC'),
+            )),
+        );
+        $this->controller = new AuthController(
+            $authenticateUser,
+            $createSession,
+        );
+    }
+
+    public function test_login_returns_user_and_cookie(): void
+    {
+        $this->createUser('correct-password');
+
+        $response = $this->controller->login(new Request([
+            'email' => 'user@example.com',
+            'password' => 'correct-password',
+        ]));
+
+        $this->assertSame(200, $response->getStatusCode());
+        $this->assertSame(
+            'user@example.com',
+            json_decode($response->getContent(), true)['user']['email'],
+        );
+        $cookie = $response->headers->getCookies()[0];
+        $this->assertSame(AuthMiddleware::COOKIE_NAME, $cookie->getName());
+        $this->assertSame('session-token', $cookie->getValue());
+        $this->assertTrue($cookie->isHttpOnly());
+        $this->assertSame('lax', $cookie->getSameSite());
+        $this->assertNotNull(
+            $this->sessionRepository->findByToken('session-token'),
+        );
+    }
+
+    public function test_login_returns_bad_request_for_missing_email(): void
+    {
+        $response = $this->controller->login(new Request([
+            'password' => 'correct-password',
+        ]));
+
+        $this->assertSame(400, $response->getStatusCode());
+        $this->assertSame(
+            ['error' => 'email is required'],
+            json_decode($response->getContent(), true),
+        );
+    }
+
+    public function test_login_returns_bad_request_for_missing_password(): void
+    {
+        $response = $this->controller->login(new Request([
+            'email' => 'user@example.com',
+        ]));
+
+        $this->assertSame(400, $response->getStatusCode());
+        $this->assertSame(
+            ['error' => 'password is required'],
+            json_decode($response->getContent(), true),
+        );
+    }
+
+    public function test_login_returns_unauthorized_for_invalid_credentials(): void
+    {
+        $this->createUser('correct-password');
+
+        $response = $this->controller->login(new Request([
+            'email' => 'user@example.com',
+            'password' => 'wrong-password',
+        ]));
+
+        $this->assertSame(401, $response->getStatusCode());
+        $this->assertSame(
+            ['error' => 'invalid credentials'],
+            json_decode($response->getContent(), true),
+        );
+    }
+
+    private function createUser(string $password): void
+    {
+        $this->userRepository->create(new CreateUserDto(
+            email: new EmailAddress('user@example.com'),
+            passwordHash: $this->passwordHasher->hash($password),
+        ));
+    }
+}
diff --git a/backend/tests/Unit/User/UserTest.php b/backend/tests/Unit/User/UserTest.php
index 0ac8d53..b3c6873 100644
--- a/backend/tests/Unit/User/UserTest.php
+++ b/backend/tests/Unit/User/UserTest.php
@@ -8,12 +8,17 @@ use PHPUnit\Framework\TestCase;
 
 class UserTest extends TestCase
 {
-    public function test_it_exposes_its_identity_and_email(): void
+    public function test_it_exposes_its_identity_email_and_password_hash(): void
     {
         $email = new EmailAddress('user@example.com');
-        $user = new User(id: 42, email: $email);
+        $user = new User(
+            id: 42,
+            email: $email,
+            passwordHash: 'hashed-password',
+        );
 
         $this->assertSame(42, $user->getId());
         $this->assertSame($email, $user->getEmail());
+        $this->assertSame('hashed-password', $user->getPasswordHash());
     }
 }
diff --git a/frontend/website/cypress/e2e/login.cy.ts b/frontend/website/cypress/e2e/login.cy.ts
new file mode 100644
index 0000000..155d227
--- /dev/null
+++ b/frontend/website/cypress/e2e/login.cy.ts
@@ -0,0 +1,151 @@
+const authenticatedUser = {
+  id: 7,
+  email: 'user@example.com',
+}
+
+function fillLoginForm(): void {
+  cy.get('#login-email').type('user@example.com')
+  cy.get('#login-password').type('correct-password')
+}
+
+describe('password login', () => {
+  beforeEach(() => {
+    cy.intercept('GET', '**/api/me', {
+      statusCode: 401,
+      body: { error: 'unauthenticated' },
+    }).as('me')
+  })
+
+  it('logs in and redirects to the dashboard', () => {
+    cy.intercept('POST', '**/api/login', (request) => {
+      expect(request.body).to.deep.equal({
+        email: 'user@example.com',
+        password: 'correct-password',
+      })
+      request.reply({
+        statusCode: 200,
+        body: { user: authenticatedUser },
+      })
+    }).as('login')
+
+    cy.visit('/login')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@login')
+
+    cy.location('pathname').should('equal', '/dashboard')
+  })
+
+  it('returns to a safe internal redirect after login', () => {
+    cy.intercept('POST', '**/api/login', {
+      statusCode: 200,
+      body: { user: authenticatedUser },
+    }).as('login')
+
+    cy.visit('/login?redirect=%2Fdashboard%3Ffocus%3Dtoday')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@login')
+
+    cy.location('pathname').should('equal', '/dashboard')
+    cy.location('search').should('equal', '?focus=today')
+  })
+
+  it('ignores an unsafe redirect after login', () => {
+    cy.intercept('POST', '**/api/login', {
+      statusCode: 200,
+      body: { user: authenticatedUser },
+    }).as('login')
+
+    cy.visit('/login?redirect=https%3A%2F%2Fexample.com')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@login')
+
+    cy.location('pathname').should('equal', '/dashboard')
+  })
+
+  it('validates required login fields before submitting', () => {
+    cy.visit('/login')
+    cy.get('form').submit()
+
+    cy.get('#login-email-error')
+      .should('have.text', 'Enter a valid email address.')
+      .and('be.visible')
+    cy.get('#login-email').should('have.attr', 'aria-invalid', 'true')
+    cy.get('#login-password-error')
+      .should('have.text', 'Enter your password.')
+      .and('be.visible')
+    cy.get('#login-password').should('have.attr', 'aria-invalid', 'true')
+    cy.location('pathname').should('equal', '/login')
+  })
+
+  it('shows the backend invalid-credentials error', () => {
+    cy.intercept('POST', '**/api/login', {
+      statusCode: 401,
+      body: { error: 'invalid credentials' },
+    }).as('login')
+
+    cy.visit('/login')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@login')
+
+    cy.get('[role="alert"]')
+      .should('have.text', 'invalid credentials')
+      .and('be.visible')
+    cy.location('pathname').should('equal', '/login')
+  })
+
+  it('shows backend request errors', () => {
+    cy.intercept('POST', '**/api/login', {
+      statusCode: 400,
+      body: { error: 'email is required' },
+    }).as('login')
+
+    cy.visit('/login')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@login')
+
+    cy.get('[role="alert"]')
+      .should('have.text', 'email is required')
+      .and('be.visible')
+    cy.get('#login-email-error').should('not.exist')
+  })
+
+  it('shows a malformed-response error', () => {
+    cy.intercept('POST', '**/api/login', {
+      statusCode: 200,
+      body: { user: { id: 7 } },
+    }).as('malformedLogin')
+
+    cy.visit('/login')
+    fillLoginForm()
+    cy.get('form').submit()
+    cy.wait('@malformedLogin')
+    cy.get('[role="alert"]').should(
+      'have.text',
+      'Unable to log in. Please try again.',
+    )
+  })
+
+  it('disables the form while login is pending', () => {
+    cy.intercept('POST', '**/api/login', {
+      delay: 500,
+      statusCode: 200,
+      body: { user: authenticatedUser },
+    }).as('login')
+
+    cy.visit('/login')
+    fillLoginForm()
+    cy.get('form').submit()
+
+    cy.get('button[type="submit"]')
+      .should('be.disabled')
+      .and('have.text', 'Logging in...')
+    cy.get('#login-email').should('be.disabled')
+    cy.get('#login-password').should('be.disabled')
+    cy.wait('@login')
+  })
+})
diff --git a/frontend/website/src/components/AuthForm.vue b/frontend/website/src/components/AuthForm.vue
index 709091f..1296d51 100644
--- a/frontend/website/src/components/AuthForm.vue
+++ b/frontend/website/src/components/AuthForm.vue
@@ -1,16 +1,34 @@
 <script setup lang="ts">
 defineProps<{
   submitLabel: string
+  submittingLabel?: string
+  submitting?: boolean
+  error?: string
+}>()
+
+defineEmits<{
+  submit: []
 }>()
 </script>
 
 <template>
-  <form class="auth-form" @submit.prevent>
+  <form
+    class="auth-form"
+    :aria-busy="submitting === true ? 'true' : undefined"
+    novalidate
+    @submit.prevent="$emit('submit')"
+  >
     <div class="auth-form__fields">
       <slot></slot>
     </div>
 
-    <button type="submit">{{ submitLabel }}</button>
+    <p v-if="error !== undefined" class="auth-form__error" role="alert">
+      {{ error }}
+    </p>
+
+    <button type="submit" :disabled="submitting">
+      {{ submitting && submittingLabel ? submittingLabel : submitLabel }}
+    </button>
   </form>
 </template>
 
@@ -60,6 +78,22 @@ button:focus-visible {
   outline-offset: 0.2rem;
 }
 
+button:disabled {
+  border-color: #708079;
+  background: #708079;
+  box-shadow: none;
+  cursor: wait;
+  transform: none;
+}
+
+.auth-form__error {
+  margin: -0.65rem 0;
+  color: #a33f37;
+  font-size: 0.8rem;
+  font-weight: 650;
+  line-height: 1.5;
+}
+
 @media (prefers-reduced-motion: reduce) {
   button {
     transition: none;
diff --git a/frontend/website/src/components/AuthTextField.vue b/frontend/website/src/components/AuthTextField.vue
index e9ec98c..3e5b087 100644
--- a/frontend/website/src/components/AuthTextField.vue
+++ b/frontend/website/src/components/AuthTextField.vue
@@ -5,7 +5,20 @@ defineProps<{
   type: 'email' | 'password' | 'text'
   autocomplete: string
   placeholder: string
+  modelValue?: string
+  error?: string
+  disabled?: boolean
 }>()
+
+const emit = defineEmits<{
+  'update:modelValue': [value: string]
+}>()
+
+function updateValue(event: Event): void {
+  if (event.target instanceof HTMLInputElement) {
+    emit('update:modelValue', event.target.value)
+  }
+}
 </script>
 
 <template>
@@ -17,7 +30,15 @@ defineProps<{
       :name="id"
       :autocomplete="autocomplete"
       :placeholder="placeholder"
+      :value="modelValue"
+      :disabled="disabled"
+      :aria-invalid="error === undefined ? undefined : 'true'"
+      :aria-describedby="error === undefined ? undefined : `${id}-error`"
+      @input="updateValue"
     />
+    <p v-if="error !== undefined" :id="`${id}-error`" class="text-field__error">
+      {{ error }}
+    </p>
   </div>
 </template>
 
@@ -62,6 +83,23 @@ input:focus {
   box-shadow: 0 0 0 3px rgb(77 125 109 / 16%);
 }
 
+input[aria-invalid='true'] {
+  border-color: #a54e46;
+}
+
+input:disabled {
+  color: #67736e;
+  background: #f5f5f2;
+  cursor: not-allowed;
+}
+
+.text-field__error {
+  margin: 0;
+  color: #a33f37;
+  font-size: 0.76rem;
+  line-height: 1.4;
+}
+
 @media (prefers-reduced-motion: reduce) {
   input {
     transition: none;
diff --git a/frontend/website/src/stores/auth.ts b/frontend/website/src/stores/auth.ts
index 399a301..d720f18 100644
--- a/frontend/website/src/stores/auth.ts
+++ b/frontend/website/src/stores/auth.ts
@@ -13,7 +13,12 @@ const meResponseSchema = z.object({
   user: authUserSchema,
 })
 
+const loginErrorResponseSchema = z.object({
+  error: z.string(),
+})
+
 export type AuthUser = z.infer<typeof authUserSchema>
+export type LoginFieldErrors = Partial<Record<'email' | 'password', string>>
 
 export const useAuthStore = defineStore('auth', () => {
   const user = ref<AuthUser | null>(null)
@@ -57,11 +62,51 @@ export const useAuthStore = defineStore('auth', () => {
     }
   }
 
+  async function login(email: string, password: string): Promise<boolean> {
+    loading.value = true
+    error.value = null
+
+    try {
+      const response = await fetch(`${API_BASE}/api/login`, {
+        method: 'POST',
+        credentials: 'include',
+        headers: {
+          Accept: 'application/json',
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({ email, password }),
+      })
+      const responseBody: unknown = await response.json()
+
+      if (response.status === 200) {
+        user.value = meResponseSchema.parse(responseBody).user
+
+        return true
+      }
+
+      user.value = null
+      const errorResponse = loginErrorResponseSchema.safeParse(responseBody)
+      error.value = errorResponse.success
+        ? errorResponse.data.error
+        : 'Unable to log in. Please try again.'
+
+      return false
+    } catch {
+      user.value = null
+      error.value = 'Unable to log in. Please try again.'
+
+      return false
+    } finally {
+      loading.value = false
+    }
+  }
+
   return {
     user,
     loading,
     error,
     isAuthenticated,
     fetchMe,
+    login,
   }
 })
diff --git a/frontend/website/src/views/LoginView.vue b/frontend/website/src/views/LoginView.vue
index e4215a4..3088dec 100644
--- a/frontend/website/src/views/LoginView.vue
+++ b/frontend/website/src/views/LoginView.vue
@@ -1,7 +1,58 @@
 <script setup lang="ts">
+import { ref } from 'vue'
+import { storeToRefs } from 'pinia'
+import { useRoute, useRouter } from 'vue-router'
+import { z } from 'zod'
+
 import AuthForm from '@/components/AuthForm.vue'
 import AuthLayout from '@/components/AuthLayout.vue'
 import AuthTextField from '@/components/AuthTextField.vue'
+import { type LoginFieldErrors, useAuthStore } from '@/stores/auth'
+
+const emailSchema = z.string().email()
+const email = ref('')
+const password = ref('')
+const fieldErrors = ref<LoginFieldErrors>({})
+const authStore = useAuthStore()
+const { loading, error } = storeToRefs(authStore)
+const route = useRoute()
+const router = useRouter()
+
+async function submitLogin(): Promise<void> {
+  const normalizedEmail = email.value.trim()
+  fieldErrors.value = validateLogin(normalizedEmail, password.value)
+  if (Object.keys(fieldErrors.value).length > 0) {
+    return
+  }
+
+  const loggedIn = await authStore.login(normalizedEmail, password.value)
+  if (!loggedIn) {
+    return
+  }
+
+  await router.push(safeLoginRedirect(route.query.redirect))
+}
+
+function validateLogin(submittedEmail: string, submittedPassword: string): LoginFieldErrors {
+  const errors: LoginFieldErrors = {}
+
+  if (!emailSchema.safeParse(submittedEmail).success) {
+    errors.email = 'Enter a valid email address.'
+  }
+  if (submittedPassword === '') {
+    errors.password = 'Enter your password.'
+  }
+
+  return errors
+}
+
+function safeLoginRedirect(redirect: unknown): string {
+  if (typeof redirect === 'string' && redirect.startsWith('/') && !redirect.startsWith('//')) {
+    return redirect
+  }
+
+  return '/dashboard'
+}
 </script>
 
 <template>
@@ -10,13 +61,22 @@ import AuthTextField from '@/components/AuthTextField.vue'
     title="Welcome back"
     description="Pick up where you left off and keep your momentum going."
   >
-    <AuthForm submit-label="Log in">
+    <AuthForm
+      submit-label="Log in"
+      submitting-label="Logging in..."
+      :submitting="loading"
+      :error="error ?? undefined"
+      @submit="submitLogin"
+    >
       <AuthTextField
         id="login-email"
         label="Email address"
         type="email"
         autocomplete="email"
         placeholder="you@example.com"
+        v-model="email"
+        :error="fieldErrors.email"
+        :disabled="loading"
       />
       <AuthTextField
         id="login-password"
@@ -24,6 +84,9 @@ import AuthTextField from '@/components/AuthTextField.vue'
         type="password"
         autocomplete="current-password"
         placeholder="Enter your password"
+        v-model="password"
+        :error="fieldErrors.password"
+        :disabled="loading"
       />
     </AuthForm>
 
diff --git a/justfile b/justfile
new file mode 100644
index 0000000..37b0450
--- /dev/null
+++ b/justfile
@@ -0,0 +1,7 @@
+set shell := ["bash", "-c"]
+
+default:
+    @just --list
+
+fresh:
+    cd backend && php artisan migrate:fresh --seed
diff --git a/process-compose.yaml b/process-compose.yaml
index fcddf50..8eb2d32 100644
--- a/process-compose.yaml
+++ b/process-compose.yaml
@@ -11,20 +11,6 @@ processes:
       initial_delay_seconds: 1
       period_seconds: 2
 
-  migrate:
-    command: php artisan migrate --force
-    working_dir: ./backend
-    depends_on:
-      postgres:
-        condition: process_healthy
-
-  seed:
-    command: php artisan db:seed --force
-    working_dir: ./backend
-    depends_on:
-      migrate:
-        condition: process_completed_successfully
-
   mailpit:
     command: mailpit --smtp 127.0.0.1:${MAILPIT_SMTP_PORT:-2525} --listen 127.0.0.1:${MAILPIT_UI_PORT:-8025}
     readiness_probe:
@@ -39,8 +25,8 @@ processes:
     command: php artisan serve --host=127.0.0.1 --port=${BACKEND_PORT:-8001}
     working_dir: ./backend
     depends_on:
-      seed:
-        condition: process_completed_successfully
+      postgres:
+        condition: process_healthy
       mailpit:
         condition: process_healthy
     readiness_probe: